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cjs247

Throttle Body Sync

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cjs247
First off I wanted to say I'm not a mechanic I research and then do it. I suppose there are a lot of people like that so take this for what it is worth. I made my manometer using 3/16 clear vinyl tubing. I purchased 2 10' lengths of tubing and 2 barbed couplers. I found a piece of particle board and used some rope light clips and zip ties to put the tubing on the board. I then filled the tubing with ATF (I liked the red color).
http://i1065.photobucket.com/albums/u389/cjs247/image.jpg2_zpsbista36h.jpg
 
After considering taking everything apart vs trying to reach the throttle bodies with everything fully assembled I opted to try it fully assembled. The throttle bodies are located under the gas tank, at the front of the motor through the frame. Accessing them does require patients and the proper tools. I used a 7" pair of forceps and a pair of 7" 45 degree needle nose pliers.  To adjust the throttle body I used a flexible carburetor adjusting screw driver. 
 
http://i1065.photobucket.com/albums/u389/cjs247/bbfe336a-1786-47d7-9833-df6895afee8d_zpsqsjxabar.jpg
This photo shows the left side throttle body hose that must be taken off. The black hose with the red line on it is slid off revealing a brass post. This where you will put the left side hose on your manometer. On a side note,  after trying the 3/16" tubing I would recommend something slightly smaller. The tubing slipped over the post no problem, but was to loose to create a good seal. I had to use zip ties around the tubing to create a good seal. Hose clamps would also work, but your already working in a tight space, so the bulk might be a problem. 
 
http://i1065.photobucket.com/albums/u389/cjs247/3afb72ce-d9be-4b05-bc87-83febc64a3d8_zpsjfoqiv44.jpg
This is the right side throttle body.  In the photo you can see the rubber cap over the brass post.  It is being secured with a small spring clip. This is where the forceps or pliers come in handy. I used the forceps.  I slipped the spring clip toward the top of the cap, but not completely off.  I then slipped the cap off. The right side of the manometer is slipped over this brass post. I used a zip tie on this side too. 
 
A couple of other things to mention too. The engine must be warmed to normal operating temperature to do the sync. For this reason I recommend wearing a pair of mechanics gloves or some sort of protection for your hands, unless you like them being roasted on you motor. Also keep your legs away from the exhaust. I saw a nice blister somewhere on this forum. I also recommend having someone help you. The reason for this in my case was that after realizing at first that I didn't have a good seal on the throttle bodies the helper could watch the manometer in case the vacuum is broke and the fluid would suck toward the motor. In this case they could kill the engine before it makes there. Also you only adjust the right side. From what I've read and watched via YouTube cylinder 1, or the one on the left, is synced to the computer. Adjusting it could cause serious problems. 
 
http://i1065.photobucket.com/albums/u389/cjs247/3f1a4ca0-b61e-46fc-842a-cd99e4059f4a_zpsltlameut.jpg
This is the photo of the adjustment screw. It's brass in color and very sensitive I was very surprised at how little the screw needed to move for adjustment.  Adjusting the screw with the flexible screw driver and keeping an eye on the manometer until the cylinders were even did take some patience because of the sensitivity of the screw.
 
At the start cylinder 1 was pulling more than 2. I have no measurement of how much, but it was out of sync.  I'm not sure that I can tell that it runs any smoother than before. I somewhat think just the satisfaction of working on my bike makes me think it's smoother. The loss of vacuum when I first started caused the check engine light to come on and code 14 to display. After putting the bike back together the check engine light  and code went off immediately. 
 
Overall this isn't difficult to do however in the future I may purchase a real manometer. Having specific adjustments to look for and measurements will be worth it. Not to mention the correct size hose to place on the throttle bodies. Give it a try if you want the satisfaction and like to save money. 
 
 
 
 
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cjs247
I also wanted to thank all of the people who have already posted info on this. It made it much easier to locate info on doing this myself. 

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Cruizin
Great writeup!!

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Guest Ralph
Great how to, some bikes have a tube on both bodies the extra one is
used to power a flap in the air box to bypass the snorkel mine as this.
 

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hobbs
Nice write up. I had a bad time with mine. I couldn't get a seal to save my life and nearly sucked a bunch of oil into the TB.
 
Lesson learned, stopping to get it done today. $20 I don't need to spend, but I need a break from wrenching after this long weekend of maintenance.

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sorkyah
Great writeup, but i think your links are broken @cjs247

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rick
Not sure where that left side hose goes to, but the service manual calls for installing a T at that fitting so that it can remain attached while doing the sync. Would think that if there's a hose on the right side port , a T there would be in order as well.
 
Long forceps are sure handy things to have. So are inspection mirrors and LED flash lights when you drop that darn plug trying to put it back on - Doh!
 
nice write-up.
 
 

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Guest Ralph
Think the left goes to a manifold pressure sensor, anyway I
put a T in both lines when I did mine.

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jerryv
What's the inside diameter of that hose? anyone know?

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rick
just a guess - a bit less than 5mm?

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rick
Think the left goes to a manifold pressure sensor, anyway I put a T in both lines when I did mine.
 the check engine light will come on if the motor runs w/o that left TB hose connected. Don't ask how I know 
would not surprise me if it also went to the fuel pump pressure regulator. Having engine vacuum there is common.
 

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